Paging and alarm system



. 3, 1963 J. B. BASSETT PAGING AND ALARM SYSTEM 2 Sheets-Sheet 1 FiledD96. -18, 1959 K C A R G N G R A H c REST POSITION Dec. 3, 1963 J. B.BASSETT PAGING AND ALARM SYSTEM Fild Dec. 18, 1959 2 Sheets-Sheet 2 L .EL I 72 86 g I I P T q I 89 l w l 90 L TRANSMITTER y United States PatentOfiice snags) Patented Dec. 3, 1963 3,113,270 PAGING AND ALARM SYSTEM.l'ohn Easier Bassett, Madison, (301111., assignor to Standard ResearchConsuitants, lino, New York, N.Y., a corporation of America Filed Dec.18, 1959, Ser. No. 869,452 7 Claims. (Cl. 32555) This invention relatesto paging systems and more particularly to security or alarm systems.

Heretofore in known security or alarm systems guards or other securitypersonnel had been alerted to the fact that something is wrong by usingan audio or visual alarm generally without identification as to thespecific location from which the alarm is sounded. Closed-circuittelevision has recently been used in security or protective systems, asfor example, in banks. The TV systems are complex and expensive; theyrequire a plurality of TV cameras along with a complex consolearrangement in which monitor receivers are housed for receiving thepicture transmitted from their respective cameras. The monitors must beconstantly observed by a guard.

It is a principal object of the present invention to provide a simple,inexpensive and eflective wireless security or alarm system fortransmitting an alarm signal to guards and other appointed personswithout others knowing the fact that the transmission is being made.

Another object is to provide a security system by which a callingstation or point from which transmission is made is identified so thatsecurity personnel may be alerted to the existence of trouble at thispoint and collective action can be taken to correct the trouble, as forexample, the guards can collectively converge at the point oftransmission.

A feature of the security system according to the invention is thatdistress calls, alarms or other information can be transmitted throughthe air to guards and to any appointed persons identifying any ofseveral transmission points at which the call or alarm has beeninitiated and doing so quietly and unknown to other persons as indicatedheretofore. Calls are initiated by push-buttons or other noiselesselectric switches by single momentary contact. These switches can beactuated manually, or by foot or knee pressure, or they can be operatedautomatically, for example, by the motion of doors, windows, etc, inknown manner. Alternatively this can be a maintained contact, or theopening of a normally closed contact. The system includes remotetransmitting equipment, which is constantly in stand-by operatingcondition, which instantly starts sending out a signal identifying thesending station and its general location, or other desired codedmessages, upon actuation of a push-button or noiseless switch. Thissignal can be repeated several times and then be shut off automatically,or it can alternatively continue until shut off by manual actuation ofone of any number of conveniently located stop buttons.

In order to receive the call signals each guard carries a small pockettransistorized receiver and is able to hear the signal as a series ofhumming or buzzing sounds suitably coded to identify the calling point.The hum can be of different tones, to designate different areas,simultaneously transmitted with the code identification of the exactpoint of the call within a given area. The individual receivers can beconstructed with a visual signal means, as

for example, one or more small lamps energized on reception of the callsignal. This light can be used instead of or at the same time that theaudio means is employed.

especially valuable feature of the system is the mobility of the guards,since they are free to move about, attend to routine duties, mingle withemployees and visitors, observe the actions of all persons and maintaingen eral supervision Without hindrance. They are not restricted to fixedprobably conspicuous booths or stations in order to receive distresscalls, and the calls are still secret so as not to alarm others.

Another feature of the system is that the transmitter can be modified sothat recorded or voice calls can be transmitted to the receivers inaddition to coded signals or in place of them.

Other features or advantages of the protective system in accordance withthe present invention will be better understood as described in thefollowing specification and appended claims in conjunction with thefollowing drawin s in which: l

FIG. la is a schematic diagram of transmitter circuitry and isillustrative of a relay and code switching section of a remotetransmitter apparatus of the security system according to the invention;

FIG. lb is a schematic diagram of the circuits of the transmittingequipment and the circuit of an individual portable receiver usable aspart of the protective system.

While the protective system in accordance with the invention will bedescribed as applicable to a bank for the security thereof it will beunderstood the system is usable anywhere where such systems are employedsuch as stores, warehouses, etc. i

According to the drawings a remote transmitting station is provided on atransmitter apparatus comprising a relay and code switching section,FIG. 1a, for keying electron tube transmitting equipment as hereafterdisclosed. The relay section is provided with a plurality ofpushbuttons, as for example, twenty push-buttons, 1-19 and IL-Ztlarranged at separate caling points. The pushbuttons are divided into twogroups of ten to represent two areas, A and B, each with ten callingstations or points from which an alarm signal can be initiated. Thepush-buttons are disposed at points which may need to transmit an alarm.For example, assuming that the security system is in a bank, the severalcalling stations may be teller positions or cages so that each tellercan easily transmit a call or alarm to guards equipped with individualreceivers as later hereinafter disclosed. it being understood that theindividual switch or push-button is conveniently located so that it canbe actuated, without anyone observing the operation, for example, bypressing it with the knee or foot.

iEach push-button is connected to a common terminal 21 0 none side andto its individual terminal on the otl er through leads 2i and 23respectively and thus to a respective relay, 1A to 16A and MB to ZtiB.In order to simplify the drawings only a few of the push-buttons andassociated relays are shown. Each relay is of the three pole doublethrow type, for example, contacts 1,, l and 1, represent the three polesof relay 1A. Contacts 1th,, 1th,, lil to 2th,, 2th, and Ztl are shownoperatively associated with respective relays 10A to 203.

A multi-position multi-deck rotary switch 24 is provided for initiatingcoded signals as hereinafter described.

3 The switch 24- is driven by a motor 25 electrically connected to apower supply source 26. The speed at which the motor drives the switch24 is related to the nurnber of switch contacts in switch 24 and is inthe range of one to ten revolutions per minute. Switch 24 is acontinuous notation type switch breaking between contacts. Its decks,for example deck 24 are wired to give the desired codes representativeof the various call points. The contacts are selected by the relaycontacts i 2 etc. For example, contacts 26 and 27 are connected so thatthey can be placed in circuit or selected by contacts 1 and 2 whenrelays 1A and 2A are respectively energized. Switch 24 is constructedwith an upper deck in which only one contact 2% is providedcorresponding to a rest position at which the switch rests when in astop condition. Contact 223 is electrically connected to a relay 29having contacts 2%, 29 and functioning as later disclosed.

Switch M is constructed so that a rotary contact 3% establishes acircuit to contact 2% from a rectifier bridge circuit 31 supplied withpower from power supply 26 through a transformer 32. Other rotarycontacts 33, 34-, 35 are electrically connected to a rectifier bridgecircuit 36 also supplied with power through a secondary winding oftransformer 32 as shown. Filament connections or leads '37, 38 areprovided in the secondary of transformer 32 for use hereinafterdisclosed.

A relay 4% is provided having its operating coil electrically energizedfrom circuit 31 and a movable contact is, for establishing .a circuitthrough to motor 25 from supply source 26 through leads 43, 45. Relay4%) is of the three pole idouble throw type and has contacts 45),,normally open and contact th normally closed. Movable contact 4d,,connects terminal 21 electrically to bridge circuit 31 through lead 46so that the relays can be electrically energized from across bridgecircuit 31 through leads 46 and 47.

A time delay relay is connected across the power supply 26 by leads 43,45 and 51 is provided with a normally open contact 5 operable to aclosed position when relay 50* is energized for controlling the numberof revolutions that motor 25 can make during the time delay period ofrelay '59. Time delay relay so controls the repetitions of a code signalto be transmitted by the calling station in a manner hereinafterdisclosed.

A four pole single throw relay 53 electrically connected to relays 113to ZllB of area B and energizable only in the event that push-buttons 11through 2.0 are actuated is provided with four contacts 53 53 53 and 5%,all of which are normally open.

Assuming that an alarm is to be transmitted from calling station 1, inarea A, pushabutton l is operated allowing relay 1A to be electricallyenergized thereby closing its contacts. Contact 1 being a double throwcontact, will disconnect any unwanted 0 contacts to the right of itshown in the lower right hand corner of FIG. 1a. Contact 1., acting as aholding contact seals in and holds the relay 1A closed after thepush-button l is released. Contact l being closed relay ill iselectrically energized closing its contacts so that contact 4% acting asa holding contact seals in and holds it closed while contact 4d,, allowsthe motor 25 to be energized. Contact lil opens thereby preventinginterference by any attempt at subsequent calls during the time that analarm is being transmitted.

The motor 25 drives rotary switch 24 so that it makes a series of spacedsingle contacts, as for example, contacts 27 arranged in a code sequencesignifying or representative of call point 1. During the time eachcontact is made by switch 24 a circuit is established through leads 56across bridge circuit 36 thereby to apply plate voltage to a transmitter57 in which a carrier frequency is generated by an oscillator 59 and itsrelated oscillatory circuitry. This carrier frequency is modulated at anaudible frequency supplied by a multi-vibrator 6i employing two 4 tubeelements en, 62 with the output of each cross connected or coupledthrough capacitors 64, 65.

The modulated carrier is applied to an output stage or tube 63 where itis amplified and then fed to a trans mission loop 7d. The modulatedcarrier frequency is heand as a hum signal in the individual radioreceivers '72 carried by the guards. The tube elements of transmitter 57are provided with filament voltage in the usual manner from the leads37, 38 of transformer 32.

The tone of the hum heard in the receivers 72 is the modulationfrequency. The carrier [frequency can be chosen for the best overalldesign and will usually be below fifty kilocycles. If tie carrierfrequency is down at the audible range, below 20,000 cps, it can beemployed to transmit code signals without requiring modulation but atthe sacrifice of tone control and voice transmission if the latter isprovided for. The modulation frequency is set at any desired audiblefrequency by a potentiometer 79* and resistors '71, 72 in combinationwith capacitors 73, '74 of the multi-vibrator circuit When an alarm orcall is sent out from area A, the relay 53 remains inactive. Contacts 53and 53 remain open and the tone of the bum heard in the receiversdepends on the value of the two capacitors 73 and 74. If the alarm orcall is sent out from area B, as for example, from station llcorresponding to push-button 11 then relay 53 is electrically energizedand contacts 5-3 and 53 close connecting capacitors 73, 74 in parallelwith capacitors 64, respectively, thereby reducing the modulationfrequency. The reduction in modulation frequency lowers the tone of thehum or call signal. The change can be made to make the hum signalcorrespond to any desired interval of the musical scaleso as to bereadily distinguishable. The tone of the bum immediately indicates thearea from which the call is initiated at the very instant that the codedsignal is initiated. A number of areas can be so identified up to thelimit of recognizable intervals of the musical tone scale. Identifyingthe area from which an alarm or call is transmitted immediately permitssecurity personnel to ascertain the general area of the alarm with thespecific point or position in the area being identified by a codedsignal transmitted by the coded signal controlled by switch 24.

Those skilled in the art will immediately perceive that tone change incoding can be combined in various ways to advantage. If the number ofcalling points is not too great the points themselves can be identifiedentirely by tone without coding.

As indicated heretofore a distress call sent out by the transmitter willbe repeated a certain number of times be- [fore stopping automatically.The number of repetitions is determined by the number of code signalsthe rotary switch 24 can give per revolution times the number ofrevolutions permitted by the timing relay St For example, if switch 24has twenty contacts per deck then one deck can be connected to conductto nine twice per revolution. Now if relay so is constructed to closebefore switch 24 completes one revolution then relay 2.9 will operate tostop switch 24 so that rotary contact 30 is at rest position 28 at theend of its first revolution. At the same time, contacts 2% and 2% willopen and reset all the other relays. However, if relay 5b is set toclose after one revolution and before the second revolution the rotaryswitch 24 will go past its rest position once and stop when it completesthe second revolution thus counting up to nine four times. By employinga plug-in thermo-type relay as relay Stl it can be changed readily topermit any desired number of revolutions of switch 24. On the otherhand, if relay Si! is removed permanently or disconnected electrically,as for example, by a disconnect switch, not shown, then switch 24 willbe driven continuously once started and the distress call will berepeated until a stop button 8b is depressed or the relay 50 is restoredto operation.

The loop 74 is tuned to resonate at the carrier frequency and is capableof creating an alternating electromagnetic field for transmission ofsignals, as is known and currently employed in the art. Thiselectromagnetic field comprises both an induction field and a radiationfield,

The transistorized radio receivers are provided with vertical ferriterod antennas '82 to pick up the electro magnetic field from loop 70 byinduction. A transistor 85 and associated circuitry are provided fordetecting the modulation of the incoming signal and a trmisistorr 84provides one of several amplifying stages so that the modulationfrequency transmitted, Whether a hum or voice message, is audible in areproducer which may be a speaker '86, or earphones not shown. It willbe understood that the transistorized receivers as shown, are of thetype employing four or five transistors and the intermediate stages notshown, are resistance and capacity coupled in known manner. For greatersensitivity, where required, more transistors in a superhetero'dyne or asuperregenerative circuit may be used.

The individual receivers 72 are provided with a battery 83 connected toprovide biasing voltages for the transistors 34 and 85. The battery 88is rechargeable through external contacts 89, 95) which are disposed 'onthe receiver housing, not shown, and cooperate with a pair of directcurrent charging contacts 91, 92 electrically connected, to the bridgerectifier circuit 31, FIG. 1a, of a charging rack in which theindividual receivers are stored when not in use. Other pairs of chargingcontacts are provided in the charging rack as shown for the individualrespective receivers.

The receivers may be constructed with tuned relay contacts, not shown,in series with the phones or reproducer in known manner to emit a louderbuzzing sound in locations where this is permissible and desirable. Onthe other hand, in locations where the signal must not be heard by anyother person than the person carrying the receiver earphones may beprovided connected to the receiver with a cord and worn in any of theknown ways such as in the ear, behind it or in an earpiece of hornrimmed glasses. Moreover, a small loudspeaker may be concealed on theperson so as to be heard of felt by the wearer but not others.

The receivers do not provide for a callback system. In locations wherethis feature is desirable a Wired intercommunication system can beincluded connecting the transmitting station with any number of call-instations in a two-way communication system so that when a signal isreceived in the transmitter the one carrying the receiver may call in tothe transmitting station.

it will be understood by those skilled in the art that the transmittingrequency, and the loop type antenna, described above, are not essentialto the operation of the s stem. There is no inherent requirementregarding either one, a higher or lower frequency can be employed in anyof the available bands, and various type antennas suited to the chosenirequency can be used.

While a preferred embodiment of the invention has been shown anddescribed it will be understood that many modifications and changes canbe made within the Scope of the invention.

What I claim and desire to secure by letters patent is:

l. In a paging and alarm system in combination, remote transmissionequipment for generating and transmitting electromagnetic Wavescorresponding to coded call signals, means comprising separate switchingmeans at separate call stations remote from the transmission equipmentand connected thereto for initiating the call signals in an individualcode representative of the call station initiating the call signal andtone-coded to an individual tone a tone representative of a geographicalarea in which said call station is located, and a plurality of portableindividual receivers for receiving the coded call signals.

2. In a paging and alarm system in combination, a

loop antenna, remote transmission equipment for generat ing andtransmitting from said antenna electromagnetic waves corresponding tocoded call signals, a switching section in said equipment comprisingseparate individual switching means at separate call stations remotefrom the transmission equipment for initiating the call signals in anindividual code representative of the call station initiating the callsignal and tone-coded to an individual tone a tone representative of ageographical area in which said call station is located, and a pluralityof portable individual receivers for receiving the coded call signals.

3. In a paging and alarm system in combination, a loop antenna, remotetransmission equipment for generating and transmitting from said antennaelectromagnetic waves corresponding to coded call signals, a switchingsection in said transmission equipment comprising separate individualswitching means at separate call stations remote from the transmissionequipment and a rotary switch for initiating the call signals in anindividual code representative of the call station initiating the callsignal means in said equipment responsive to the individual switchingmeans for initiating the call signal tonecoded to an individual tone atone representative of a geographical area in which said call station islocated, and a plurality of portable individual receivers tor receivingthe coded call signals.

4. In a paging and alarm system in combination, a loop antenna, remotetransmission equipment for generating and transmitting from said antennaelectromagnetic Waves corresponding to coded call signals, a switchingsection in said transmission equipment comprising separate, individualswitching means at separate call stations, remote from the transmissionequipment and a driven rotary switch for initiating the call signals inan individual code representative of the call station initiating thecall signal, multi-vibrator means in said equipment responsive to theswitching means for initiating the individual call signals tone-coded toindividual tones representative of individual respective geographicalareas in which said call stations are located, a plurality of portableindividual receivers for receiving the coded call signals, meansconnecting said switching means in a plurality of groups and each groupconnected in a respective geographical area.

5. In a paging and alarm system in combination, a loop antenna, remotetransmission equipment for generating and transmitting from said antennaelectromagnetic Waves corresponding to coded call signals, meanscomprising separate switching means at separate call stations, remotefrom the transmission equipment and circuit interrupting means forinitiating the call signals in an individual code representative of thecall station initiating the call signal, means connecting said switchingmeans in a plurality of groups, each group being disposed in arespective geographical area, means in said equipment responsive to theindividual switching means for initiating the call signal tone coded toa given tone representative of a geographical area in which said callstation is located, and a plurality of portable individual receivers forreceiving the coded call signals.

6. In a paging and alarm system in combination, a loop antenna, remotetransmission equipment for generating and transmitting on said antennaelectromagnetic Waves corresponding to coded call signals, meanscomprising separate switching means, at separate call stations, remotefrom the transmission equipment for initiating the call signalstone-coded to an individual tone code representative of the call stationinitiating the call signal, capacitance means in said equipment to varythe tone of the call, and a plurality of portable individual receiversfor receiving the coded call signals.

7. In a paging and alarm system in combination, a loop antenna, remotetransmission equipment for generating and transmitting from said antennaelectromagnetic waves corresponding to coded call signals, a switchingsection in said equipment comprising separate means comprisingindividual switching" means at separate call stations remote from thetransmission equipment for initiating the call signals in an individualcode representative of the call station initiating the call signal andtone-coded 5 to an individual tone corresponding to a tonerepresentative of a geographical area in which said call station islocated, said means for initiating said call signals including means torepeat the individual ca-ll signals indefinitely and dfor a preselectedperiod of time once initiated and 10 means to terminate the individualcalls at will, and a plurality of portable individual receivers forreceiving the coded call signals.

References Cited in the file of this patent UNITED sTATis- PATENTS WareDec. 6, Cumming Sept. 10; Bell Oct. 26, Kirpatrick Apr. 3, Fischler Nov.13, DeGTaaf Jan. 20, Varley Feb. 17, Crow et al. Aug. 11,

1. IN A PAGING AND ALARM SYSTEM IN COMBINATION, REMOTE TRANSMISSIONEQUIPMENT FOR GENERATING AND TRANSMITTING ELECTROMAGNETIC WAVESCORRESPONDING TO CODED CALL SIGNALS, MEANS COMPRISING SEPARATE SWITCHINGMEANS AT SEPARATE CALL STATIONS REMOTE FROM THE TRANSMISSION EQUIPMENTAND CONNECTED THERETO FOR INITIATING THE CALL SIGNALS IN AN INDIVIDUALCODE REPRESENTATIVE OF THE CALL STATION INITIATING THE CALL SIGNAL ANDTONE-CODED TO AN INDIVIDUAL TONE A TONE REPRESENTATIVE OF A GEOGRAPHICALAREA IN WHICH SAID CALL STATION IS LOCATED, AND A PLURALITY OF PORTABLEINDIVIDUAL RECEIVERS FOR RECEIVING THE CODED CALL SIGNALS.